Insects

Front 1

1. Order Odonata – dragonflies and damselflies

Back 1

Note inability to completely fold wings and fact that wings have numerous veins–both indicate a primitive
condition in insects. You will not have to differentiate between dragonflies and damselflies. Either
common name will suffice on an exam. Nymphs (juvenile stage, also called naiads) are aquatic; both
nymphs and adults are predacious. The naiads feed on a variety of food including aquatic insects,
tadpoles, crustaceans, fish, and each other. The adults are strong fliers capable of capturing many types
of insects in flight. They do this by forming their legs into a basket and scooping up their prey in flight.
Damselflies are weaker fliers than dragonflies and feed on less active prey.

Front 2

Order Orthoptera

Back 2

grasshoppers, crickets, katydids, walking sticks, cockroaches

Front 3

short-horned grasshoppers

Back 3

this group contains our most common grasshoppers.
They are plant feeders (phytophagous) and many are important pests of cultivated plants. Most of them
oviposit (lay eggs) in the ground and overwinter in the egg stage.

Front 4

green katydids

Back 4

note camouflaged wings; many stridulate (produce sound
through friction).

Front 5

crickets

Back 5

this group contains many common insects and the males are well-known
songsters. The light-colored crickets (Subfamily Oecanthinae) are the tree crickets. The song of most
species of tree crickets is a prolonged trill.

Front 6

walking sticks

Back 6

great mimics; these insects strongly resemble twigs and are
usually found on trees and shrubs. They are phytophagous.

Front 7

cockroaches

Back 7

the best-known cockroaches are those that invade houses, where they
may be serious pests. They feed on a variety of foods and have an unpleasant odor. They hide in cracks
during the day and feed at night. All are active, fast-running insects; many species seldom if ever fly.

Front 8

Order Homoptera

Back 8

cicadas, leafhoppers, treehoppers, aphids

Front 9

cicadas

Back 9

cicadas are common phytophagous insects but are more often heard than
seen since the majority are arboreal (live in trees). Sound is produced only by males and is usually a loud
(sometimes pulsating) buzz. Most cicadas are large, blackish insects with greenish markings, that appeareach year in early July and August. Their life cycle lasts 2-5 or more years. Eggs are laid in twigs, which
usually die and break off; nymphs live in the ground and feed on roots. Some species have a 13 or 17 year
life cycle. They are often improperly referred to as “locusts” because of their plaguelike mass emergences,
but they are not really related or similar to the migratory locusts of the Old World.

Front 10

treehoppers

Back 10

phytophagous; treehoppers are easily recognized by the enlarged
pronotum (an enlarged exoskeleton plate derived from the thorax), which covers the thorax and abdomen
and usually projects forward over the head as well. Treehoppers may appear thorn-like, humpbacked, or
lobed. Like aphids (also homopterans), the nymphs (and occasionally the adults) of many species are
tended (much like farmers tend their milk cows) by ants because of the sweet secretions (honeydew) they
produce

Front 11

Order Hemiptera

Back 11

true bugs, with the first pair of wings (forewings) called hemelytra. The hemelytra
have a leathery anterior part and the posterior portion is membranous. These forewings lay flat over the
back of the abdomen and typically overlap at the tip when not in use.

Front 12

giant water bugs

Back 12

aquatic insect; common predators of insects and
small minnows in ponds, streams, etc. Their flattened hindlegs are used for swimming. The forelegs grasp
prey while the insect thrusts its powerful beak into its victim. Note modification of anterior pair of legs
with grooved femora to accommodate tibiae when folded tightly.

Front 13

water striders

Back 13

usually found running about on the surface of water. Gerrids are
common on the surface of slow streams and ponds. They feed on various small insects that fall onto the
water surface. They do not bite humans.

Front 14

stink bugs

Back 14

the name comes from the disagreeable odor these bugs produce. Both
adults and nymphs possess large stink glands located that open through slits on the ventral surface. Most
are phytophagous but some are predacious.

Front 15

waterscorpions

Back 15

waterscorpions are predaceous on other insects and can inflict a
painful bite if handled carelessly. Note the paired tail-like breathing tubes used to obtain oxygen while
submerged.

Front 16

Order Anoplura

Back 16

sucking lice

Front 17

Pediculus humanus,

Back 17

human louse, vector of louse-borne typhus, trench fever and
epidemic relapsing fever.

Front 18

Hemimetabolous insects

Back 18

insects with incomplete metamorphosis; immature forms (called nymphs) are
similar to adults

Front 19

Holometabolous insects

Back 19

insects with complete metamorphosis; immature forms (called larvae) and adults
differ greatly in body form and frequently habits as well.

Front 20

Order Neuroptera

Back 20

nerve-winged insects

Front 21

green lacewings

Back 21

green lacewings are very common insects, found on grass,
weeds, and shrubs, usually in relatively open areas. They often give off an unpleasant odor when handled.
Adults and larvae feed principally on aphids and are important agents in the control of these insects.

Front 22

Order Coleoptera

Back 22

beetles; (hardened outer wings known as an elytra). Note that the elytra meet in a
straight line down the back.

Front 23

tiger beetles

Back 23

predaceous; they inhabit a variety of habitats, including beaches,
sand dunes, sand pits, trails, woodland openings, and barren hillsides. Active mostly on warm, sunny
days. The larvae construct special burrows in the ground and ambush unsuspecting prey that pass within
reach.

Front 24

ground beetles

Back 24

a great number of species occur in North America generally
beneficial due to predation on other insects (one species feeds on garden slugs). Many are omnivorous,
while others feed exclusively on seeds and herbaceous plants. Note the conspicuous prothorax, narrow
head, and long legs

Front 25

whirligig beetles

Back 25

these beetles are often seen swimming in groups in an odd
gyrating fashion on the surface of ponds and streams. Their two pairs of compound eyes enable them to
watch for enemies and prey both above and below the water surface. Adults and larvae are predaceous.
Some adults when handled give off an odor similar to that of pineapple.

Front 26

stag beetles

Back 26

most adult stag beetles feed on sap flows; larvae live in decaying logs
and stumps and apparently feed on juices of rotting wood. The greatly developed and sometimes branched
mandibles of the males of a few species give these beetles their common name.

Front 27

Japanese beetle

Back 27

a major pest of shrubs and trees in the eastern and midwestern
U.S.; a bacteria, Bacillus thuringensis has been fairly successful in controlling it but the beetle has so
many host plants that it is difficult to keep up with it; larvae feed on roots of grasses and shrubs while
adults defoliate branches.

Front 28

click beetles

Back 28

larvae are known as wireworms and feed on roots of economically
important plants such as corn and other members of the grass family. A spine on the ventral side of an
adult can be flipped down or "clicked" to cause the beetle to flip up when it is on its back–hence the
common name. Note that body is usually rounded on each end.

Front 29

ladybird beetles

Back 29

both larvae and adults are beneficial as natural enemies of
aphids, mealybugs, scale insects, etc. The "black sheep" of the ladybird family is the Mexican bean beetle,
a pest of many species of beans including garden varieties.

Front 30

blister beetles

Back 30

when handled, a toxic substance exudes from the base of the legs and
will cause blistering (not all species). A substance called cantharidin has been extracted from the
exudation and is used medicinally as an aphrodisiac

Front 31

long-horned wood boring beetles

Back 31

characterized by long antennae. Many
species lay eggs in tree branches and trunks and developing larvae cause damage by tunneling; some
adults "girdle" a branch after laying eggs causing it to die; many bizarre tropical species in this family

Front 32

leaf beetles

Back 32

a very large and economically important family and are
phytophagous; they attack cereal grains, potatoes, tomatoes, grapes, asparagus, corn, etc. A very well
known species includes the Colorado potato beetle (black and white longitudinal stripes on elytra).

Front 33

Order Hymenoptera

Back 33

ants, bees and wasps

Front 34

ichneumon wasps

Back 34

note the extremely long ovipositor which is used to insert a
parasitic egg within host caterpillar; very beneficial insects that are known as parasitoids (an insect that
lives in its immature stage in or on another insect, which it kills after completing its own feeding); they
attack various stages of hosts, parasitizing both larvae or adults.

Front 35

green metallic bees

Back 35

– the female digs a nest of many branching burrows
underground or in dead wood or uses preexisting burrows of other insects. The female supplies each cell
with a pollen ball and nectar, and lays an egg on each ball. These bees can often be seen visiting flowers.
Returning bees carry impressive pollen loads on their hind legs.

Front 36

horntails

Back 36

eggs are laid in dead and dying trees and the larvae bore into the trees,
attacking both deciduous and coniferous trees; note that there is no constriction between thorax and
abdomen in this primitive group. Compare to situation in ants and higher bees and wasps.

Front 37

yellowjackets

Back 37

these wasps build nests of a papery material in walls or attics so they
are commonly encountered around buildings. Some species nest in the ground and some species nest
above ground in various protected situations. Females of these wasps inflict a very painful sting

Front 38

honey bees (small) and bumble bees (large)

Back 38

honey bees exhibit a high degree of social
behavior. They live in colonies with 3 castes: the queen is diploid and sexually mature due to diet of royal
jelly; workers (the most abundant and most commonly seen) are also diploid but sexually immature due to
diet; drones are males and are haploid. Honey bees are extremely valuable not only for the honey and
beeswax they produce but because of their pollinating activities. Bumble bees are also social with three
castes. Most bumble bees nest in or on the ground, often in a deserted mouse nest.

Front 39

ants

Back 39

This is a large and widely distributed group. Ants are colonial and ant
colonies can vary greatly in size, from a dozen or so to many thousands. Note winged (reproductive) and
worker castes. Ants vary in habits: some are carnivorous, some are scavengers, and some are plant
feeders. Most ants will bite when disturbed and many will sting. A few can eject a foul smelling secretion
from the anus.

Front 40

Order Diptera

Back 40

true flies; dipterans have only 1 pair of wings

Front 41

flower flies

Back 41

many are mimics of bees and wasps; these flies do not sting but collect
nectar and sap from flowers.

Front 42

blow flies

Back 42

this is a large group of flies and its members are often common and
abundant. Many are metallic bluish or green. Larvae are generally scavengers, living in carrion, dung, and
similar materials; most maggots one finds in the body of a dead animal are blow fly larvae. Very
important scavengers in that they help reduce carrion and garbage to small volumes

Front 43

crane flies

Back 43

common and abundant, these medium- to large-sized, long-legged,
mosquito-like flies do not bite. Larvae live in water or moist soil, and generally feed on decaying plant
material. Adults are most common near water or where there is abundant vegetation.

Front 44

Order Lepidoptera

Back 44

butterflies and moths

Front 45

monarchs

Back 45

the milkweed butterfly; unpalatable to predators and thus serve as models
for viceroy butterflies which belong to a different family and are palatable. Viceroys thus function as
mimics. The host plant for monarchs is milkweed which has toxic chemicals taken up by the various
species that feed on them and are stored in the body, thus protecting the monarch and other species that
feed on milkweed from predators

Front 46

viceroy

Back 46

mimics in the monarch-viceroy complex

Front 47

brush-footed butterflies

Back 47

includes many common species of butterflies

Front 48

sulfurs

Back 48

yellow and white; feed on a variety of plants including cabbages (as larvae);
very common.

Front 49

tent caterpillars

Back 49

larvae are gregarious and some species construct a silken
tent, usually in the fork of a branch, and use it as a shelter.

Front 50

swallowtails

Back 50

all are graceful fliers.

Front 51

giant silkworm moths

Back 51

this group includes our largest moths, some of which have
a wingspan of six inches. The mature larvae produce large cocoons of silk and leaf material, which are
often attached to leaf twigs. Mostly nocturnal.

Front 52

sphinx or hawk moths

Back 52

sphinx moths are strong fliers, with a very rapid wingbeat.
They feed on flowers, much like hummingbirds. Most species feed at dusk or at night; a few feed during
the day. Some are pests of tomatoes, tobacco, and other plants.

Front 53

Order Siphonaptera

Back 53

Fleas, being ectoparasites, have also secondarily lost their wings. Fleas appear to have evolved from a
group of flies probably during the early evolution and adaptive radiation of birds and mammals (all
known fleas are restricted to these two groups of hosts today). Fleas tend to be compressed laterally
(rather than dorsoventrally as in lice), have backward projecting hairs (setae) and have highly modified
hind legs suited for jumping.
Research in England has shown that the & flea can regulate her egg production to correspond with the
gestation cycle of the mammalian host. For example, a flea feeding on the blood of a host rabbit (&) will
suck up reproductive hormones in the blood and be physiologically stimulated to produce eggs of her own.
The mechanism basically insures that baby rabbits will acquire their own population of fleas.

Front 54

Xenopsylla cheopis

Back 54

the oriental rat flea, principal vector of bubonic plague,
endemic typhus and serves as an intermediate host for the tapeworm Hymenolepis diminuta.